Collapsible bottle

ABSTRACT

A collapsible or foldable plastic bottle of circular bellows like configuration capable of manufacture on current plastic bottle manufacturing equipment with current plastic materials approved for contact with foods and beverages. The bellows over center and fold to retain the folded condition without external assistance thus providing a self-latching feature. In particular, the bellows of the bottle, when fully folded, cause the bottle to substantially fit within a cup fastened to the base of the bottle. The cup is generally formed by further extending the cup upward and increasing the diameter slightly in comparison with the reinforcing cup on current soda pop bottles.

BACKGROUND OF THE INVENTION

The field of the invention pertains to collapsible plastic bottles andin particular to collapsible plastic bottles for foods and beverages,such as soda pop. Such bottles are constructed of plastics approved bythe Food and Drug Administration for intimate and prolonged contact withfoods and beverages. These bottles are commonly used for a variety ofbrands of soda pop and are formed of a clear plastic in a two-stagemolding process. Typically, the two-stage molding process comprises aninjection molded preform that is subsequently positioned in a bottlemold and blown to the full size of the bottle. In so doing, the sidewall of the preform as the bottle is blown is stretched and tensioned tocreate an exceptionally sturdy thin-walled plastic bottle. Because theend of the preform, which eventually forms the bottom of the bottle, isnot stretched axially as is the side wall, the bottom of the bottle doesnot possess the same strength as the side wall. Therefore, a separateplastic cup is fitted and affixed to the bottom of the bottle in asubsequent operation to reinforce the bottom of the bottle and preventcracking or leakage in the handling of the filled bottle.

SUMMARY OF THE INVENTION

Applicant's invention comprises further improvements in theconfiguration of the finished bottle and in the manufacture of thefinished bottle to provide a collapsible bottle. The purpose of acollapsible bottle is to substantially eliminate the air space in thetop of the bottle as the contents are partially used. In the case ofsoda pop, a previously opened and partially filled bottle, upon storagefor a few hours, goes flat or dead to the taste. In large part this isdue to the escape of carbon dioxide dissolved in the soda pop into theair above the pop and in the bottle. By permitting the user to collapsethe vertical height of the bottle as the soda is used or just before thecap is reattached, the air space above the partially filled bottle issubstantially eliminated. With the cap on the bottle the carbon dioxidein the soda pop has no air space in which to escape.

Applicant's bottle provides a side wall circumferentially shaped in themanner of bellows. The bellows are formed to overcenter as the bottle iscollapsed thus preventing the bottle from returning to its full heightbefore or after the cap is placed on the bottle. The bellows are formedin the preferred embodiment by adding a third step to the manufacture ofthe blown bottle. After the preform is made and then is blown andstretched in the bottle mold, additional air or nitrogen is suddenlyinjected into the bottle at higher pressure to drive the alreadystretched side wall into the grooves of the mold that form the bellows.This sudden increased pressure further stretches the side wall and thinsit; in particular, over the inner circumferential ridges of the mold toform folding points or folding sections of the side wall. Thus, thebottle can be easily and quickly folded as the liquid is withdrawntherefrom. The bellows also permit the bottle to be bent over to oneside thus simulating a spout for easier pouring of the liquid inside.

The cap placed on the bottom of the bottle is slightly larger and deeperthan the conventional bottle bottom cap and is attached to the bottom ofthe collapsible bottle both to reinforce the bottom of the bottle and toprovide a pocket for the bottle to fold into. The new cap issubstantially smooth sided on the outside side wall thereof to form asuitable surface for the bottle labels in substitution for placing thelabels on the bottle side wall. The bellows configuration makesdifficult the placing of labels on the bottle itself, and the labelswould interfere with the proper folding of the bottle. Thus, the foldedbottle fits generally within the extended bottom cup of the bottle. Thecup also provides a convenient hand grip when the bottle is partially orfully collapsed.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial side cross-sectional view of the collapsible bottle;and

FIG. 2 is a partial side cross-sectional view of the collapsible bottlefully collapsed, and

FIG. 3 is a top view of the collapsible bottle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 the bottle, generally denoted by 10, includes an upperhemispherical portion 12 having a central neck 14 for a cap 16 that maybe attached and detached. The bottle 10 is formed with generallybellows-shaped sidewalls 18 and includes a separate bottom cup 20affixed to the bottom of the bottle 10. The cup 20 side wall 22 isgenerally smooth to provide a suitable surface for the labels that areaffixed to the bottle. Labels may also be affixed to the generallysmooth hemispherical portion 12 at the top of the bottle. As illustratedin FIG. 1, the bellows-shaped side wall 18 of the bottle extends downwithin the cup side wall 22 as illustrated at 24. Typically the bellowsextend almost to the bottom of the bottle and cup and the cup side wallextends generally toward the middle of the vertical height of thebottle.

Each bellow here indicated by 26 comprises a downwardly and outwardlyextending conical portion 28 and a downwardly and inwardly extendingconical portion 30 which is substantially smaller and at a much greaterangle to the axis of the bottle. In the figure six bellows are shown;however, in actual practice a very large number of bellows, each ofwhich is much smaller in proportion to the size of the bottle, ispreferred. Thus, as shown, the bellows are greatly enlarged inproportion to the typical soda bottle in which the bellows areincorporated.

FIG. 2 illustrates the bottle substantially collapsed for a volumeapproximately one-half that of the expanded bottle. Thus, the bottlesubstantially eliminates the air volume over the liquid beverage down tothe point where the bottle is half full. As shown, the individualbellows 26 are collapsed or folded over such that the short portion 30of each bellow is folded over the long portion 28 of the adjacentbellow. In FIG. 2 as in FIG. 1 the size of each bellow in proportion tothe size of the bottle is greatly exaggerated.

In actual practice the increase in diameter of the bottle attributed tothe bellows is so limited as to not substantially increase the diameterof the bottle with the cup attached. The cup side wall 22 interiordiameter need only be sufficient 23 to permit the bellows to fold overand become overcentered as shown in FIG. 2. The flexibility of the cupmaterial assists in permitting the bellows to fold and snap over. Oncesnapped over as shown in FIG. 2, because of the cylindricalconfiguration of the bottle and bellows, the bellows will not expanddespite the failure to replace the cap 16 on the bottle. The closeproximity 21 of the sidewall 22 of the cup also assists in preventingthe collapsed bellows from expanding.

The cup side wall 22 is substantially smooth to assist in attachinglabels and the like to the cup and bottle combination. The cup isadhesively affixed to the bottom of the bottle as shown at 32 in bothfigures. It is preferred that the bellows be generally shaped as shownto obtain the overcentering action that holds the bottle collapsed.However, even without the overcentering action, the attachment of thecap to the collapsed bottle prevents the bottle from expanding due tothe external atmospheric air pressure. It is envisioned that in a vastmajority of instances the plastic utilized for the bottles will be avery strong flexible plastic such as acrylonitrile or similar plasticapproved by the Food and Drug Administration. In some instances arelatively soft plastic may be utilized for the bottle in which case theovercentering action would not be completely satisfactory and thereplacement of the cap on the bottle required to retain the partiallyfull bottle in the collapsed state.

To assist in the folding and collapsing of bottles manufactured fromstretched plastics such as are typically used currently for the morepopular brands of soda pop in two liter bottles, such stretch plasticsare typically formed into bottles by first creating an injection moldedor blow molded preform having a relatively thick plastic wall and bottomand generally in the shape of a common laboratory test tube. Thepreform, heated above the heat distortion temperature of the plastic, isthen blown in a bottle mold to the full bottle size and wall thickness.In the process of blowing the bottle the side wall of the bottle isstretched, which in combination with the particular plastic addssignificantly to the tensile strength of the bottle side wall. Afterremoval from the bottle mold, the bottom cup is adhesively affixed tothe bottom of the bottle to reinforce the bottle bottom.

Applicant's bottle is manufactured in a similar manner; however, the cup20 is sized in depth and inside diameter to accommodate the collapsedbellows as shown in FIG. 2. Typically, the cup will be two or more timesthe depth of the plastic cup on the bottom of a conventional two litersoda pop bottle. In blowing the bottle, subsequent to blowing the bottlewithin the bottle mold and before removal from the bottle mold,additional high pressure air or nitrogen gas is suddenly admitted to theinterior of the bottle to expand the side wall of the bottle into thebellows forming grooves of the mold. The sudden expansion with the highpressure air or gas stretches the side wall further at the lesserdiameters of the bellows such as 34 thereby forming a stretched circularthin spot or fold ring in the bottle wall. In addition, the conicalportions 28 and 30 will be slightly stretched further as blown from thebellowless wall indicated at 36 to the final bellows configuration.

The additional thinning of the wall permits the bellows action to moreeasily take place with the plastic materials currently utilized and thewall thicknesses currently utilized. The additional thinning of the wallbeyond that of the conventional uncollapsible bottle is not detrimentalto the strength of the bottle because the ribbing effect created by thebellows configuration adds additional rigidity in all directions withthe exception of the collapsing direction of the bottle. Thus, the foldrings and thinned sections of the side wall assist in creating an easilycollapsible bottle that remains convenient for handling and storing.

Fully collapsed into the cup, the bottle remains easy to use and whencompletely emptied and stored, only takes approximately half the volumeof the conventional uncollapsible soda pop bottle. In States such asMichigan, the storage of empty bottles for return to the bottling plantsand distributors is a significant problem. Collapsible bottles cansignificantly assist in lessening the storage volumes required for largequantities of empty bottles in storage rooms before they are returned tothe reprocessor of the bottles.

I claim:
 1. A collapsible plastic .[.bottle.]. .Iadd.container.Iaddend.having a top and a base joined by a substantially cylindricalside wall integral therewith and an aperture in the top,the improvementcomprising a plurality of circular bellows formed by conical sectionsintegrally joined .Iadd.by lesser and greater diameter fold rings.Iaddend.to create at least a portion of the .[.bottle.]..Iadd.container .Iaddend.side wall, the conical sections comprisingalternating short portions and long portions, said short portions beingat a greater angle to the .[.bottle.]. .Iadd.container .Iaddend.axisthan said long portions, and the lesser diameter .[.junctures.]..Iadd.fold rings .Iaddend.of the long portions with the short portionsbeing formed with a wall thickness less than the side wall thickness ofthe portions to create fold rings for the circular bellows.
 2. Thecollapsible plastic .[.bottle.]. .Iadd.container .Iaddend.of claim 1wherein said short portions are substantially one-half the long portionsin height.
 3. The collapsible plastic .[.bottle.]. .Iadd.container.Iaddend.of claim 1 wherein the greater diameter junctures of thebellows portions increase and then decrease as the bellows are foldedover to provide a snap action over centering of the bellows therebylatching the bellows in the closed position.
 4. The collapsible plastic.[.bottle.]. .Iadd.container .Iaddend.of claim 1 including a cup affixedto the base of the .[.bottle.]. .Iadd.container.Iaddend., said cuphaving a side wall extending upwardly about the bottle side wall andspaced therefrom.
 5. The collapsible plastic .[.bottle.]..Iadd.container .Iaddend.of claim 4 wherein said cup side wall extendsapproximately one-half the height of the bottle.
 6. The collapsibleplastic .[.bottle.]. .Iadd.container .Iaddend.of claim 4 wherein theinside diameter of the cup side wall is less than the maximum outsidediameter of the bellows attained during fold over.
 7. The collapsibleplastic .[.bottle.]. .Iadd.container .Iaddend.of claim 4 wherein thebellows side wall of the .[.bottle.]. .Iadd.container .Iaddend.foldsinto the cup side wall.
 8. A collapsible plastic .[.bottle.]..Iadd.container .Iaddend.having a base and a top joined by asubstantially cylindrical side wall integral therewith and an aperturein the top,said side wall formed into a plurality of circular bellows,said circular bellows comprising a plurality of alternately upwardly anddownwardly pointed conical sections joined integrally by circular foldrings of a thickness less than the conical section thicknesses, and.Iadd.said circular bellows comprising lesser and greater diametercircular fold rings .Iaddend. said greater diameter circular fold ringsincreasing to and decreasing from a maximum diameter to provide an overcentering of the bellows during folding thereby latching the bellows inthe collapsed position.
 9. The collapsible plastic .[.bottle.]..Iadd.container .Iaddend.of claim 8 wherein the conical sections pointedin one axial direction are approximately twice the height of the otherconical sections.
 10. The collapsible plastic .[.bottle.]..Iadd.container .Iaddend.of claim 9 wherein the taller conical sectionsare at a lesser angle to the .[.bottle.]. .Iadd.container .Iaddend.axisthan the shorter conical sections.
 11. The collapsible plastic.[.bottle.]. .Iadd.container .Iaddend.of claim 8 including a cup affixedto the base of the .[.bottle.]. .Iadd.container.Iaddend., said cuphaving a side wall extending upwardly about the .[.bottle.]..Iadd.container .Iaddend.side wall and space therefrom.
 12. Thecollapsible plastic .[.bottle.]. .Iadd.container .Iaddend.of claim 11wherein said cup side wall extends approximately one-half the height ofthe .[.bottle.]. .Iadd.container.Iaddend..
 13. The collapsible plastic.[.bottle.]. .Iadd.container .Iaddend.of claim 11 wherein the insidediameter of the cup side wall is less than the maximum outside diameterof the bellows attained during fold over.
 14. The collapsible plastic.[.bottle.]. .Iadd.container .Iaddend.of claim 11 wherein the bellowsside wall of the .[.bottle.]. .Iadd.container .Iaddend.folds into thecup sidewall.
 15. A collapsible plastic .[.bottle.]. .Iadd.container.Iaddend.having a top and a base joined by a substantially cylindricalside wall integral therewith and an aperture in the top,the improvementcomprising a plurality of circular bellows formed by conical sectionsintegrally joined to create at least a portion of the .[.bottle.]..Iadd.container .Iaddend.side wall, the conical sections comprisingalternating short portions and long portions, said short portions beingat a greater angle to the .[.bottle.]. .Iadd.container .Iaddend.axisthan said long portions, and a separate cup affixed to the base of the.[.bottle.]. .Iadd.container.Iaddend., said cup having a side wallextending upwardly about the .[.bottle.]. .Iadd.container .Iaddend.sidewall and spaced therefrom to contain the folded bellows.
 16. Thecollapsible plastic .[.bottle.]. .Iadd.container .Iaddend.of claim 15wherein said short portions are substantially one-half the long portionsin height.
 17. The collapsible plastic .[.bottle.]. .Iadd.container.Iaddend.of claim 15 wherein said cup side wall extends approximatelyone-half the height of the .[.bottle.]. .Iadd.container.Iaddend.. 18.The collapsible plastic .[.bottle.]. .Iadd.container .Iaddend.of claim15 including a cap, said cap adapted to provide an air tight seal upontight engagement with the .[.bottle.]. .Iadd.container .Iaddend.aboutthe aperture, said .[.bottle.]. .Iadd.container .Iaddend.beingretainable in the collapsed condition by the tight replacement of thecap on the .[.bottle.]. .Iadd.container .Iaddend.with the .[.bottle.]..Iadd.container .Iaddend.in the collapsed condition. .Iadd.
 19. Acollapsible plastic container having a base and a top joined by asubstantially cylindrical side wall integral therewith,at least aportion of said sidewall formed into a plurality of bellows extendingtherearound, said bellows comprising upwardly and downwardly pointedsubstantially conical sections joined by fold rings, and said fold ringsretaining substantially fixed diameters and at least some of saidupwardly and downwardly pointed conical sections flexing from theunfolded to the folded position to provide an over centering of thebellows during folding thereby latching the bellows in the collapsedposition. .Iaddend. .Iadd.20. The collapsible plastic container of claim19 wherein the conical sections pointed in one axial direction areapproximately twice the height of the other conical sections. .Iaddend..Iadd.21. The collapsible plastic container of claim 19 wherein some ofthe conical sections differ in height and the shorter conical sectionsflex to provide the over centering of the bellows. .Iaddend. .Iadd.22.The collapsible plastic container of claim 19 wherein some of saidconical sections are shorter in slope than the other conical sectionsand wherein said shorter conical sections flex to provide the overcentering of the bellows. .Iaddend. .Iadd.23. The collapsible plasticcontainer of claim 19 wherein some of said conical sections differ inangular relationship to the bottle axis. .Iaddend.